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Fibers 2024

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Please wait a minute... For Selected: Download Citations EndNote Ris BibTeX Toggle Thumbnails Select One dimensional pea-shaped NiSe2 nanoparticles encapsulated in N-doped graphitic carbon fibers to boost redox reversibility in sodium-ion batteries Hyunjeong Gim, Achmad Yanuar Maulana, Jiwon Choi, Jungwook Song, Boram Yun, Yuri Jeong, Nahyun An, Myeongkee Park, Cybelle M. Futalan, Jongsik Kim J. Mater. Sci. Technol.    2023, 168: 215-226.   DOI: 10.1016/j.jmst.2023.05.048 Abstract （36）      PDF       Knowledge map    In recent years, sodium-ion batteries (SIBs) have emerged as a promising technology for energy storage systems (ESSs) because of the abundance and affordability of sodium. Recently, metal selenides have been studied as promising high-performance conversion-type anode materials in SIBs. Among them, nickel selenide (NiSe2) has received considerable attention due to its high theoretical capacity of 495 mAh g-1 and conductivity. However, it still suffers from poor cycling stability because of the low electrochemical reactivity, large volume expansion, and structural instability during cycles. To address these challenges, NiSe2 nanoparticles encapsulated in N-doped graphitic carbon fibers (NiSe2@NGCF) were synthesized by using ZIF-8 as a template. NiSe2@NGCF showed a high discharge capacity of 558.3 mAh g-1 with a fading rate of 0.14% per cycle after 200 cycles at 0.5 A g-1 in 0.01-3.0 V. At a very high current density of 5 A g-1, the capacity still displayed excellent long-term cycle life with a discharge capacity of 406.1 mAh g-1 with a fading rate of 0.016% per cycle after 3000 cycles. The mechanism of the excellent electrochemical performance of NiSe2@NGCF was thoroughly investigated by ex-situ XRD, TEM, and SEM analyses. Furthermore, NiSe2@NGCF//Na3V2(PO4)3 full-cell also delivered an excellent reversible capacity of 378.7 mAh g-1 at 0.1 A g-1 after 50 cycles, demonstrating its potential for practical application in SIBs. Reference | Related Articles | Metrics Select Hybrid assembly of conducting nanofiber network for ultra-stretchable and highly sensitive conductive hydrogels Yalei Wang, Shulong Zeng, Shaohong Shi, Yuheng Jiang, Zhiwei Du, Bingzhen Wang, Xiurong Li J. Mater. Sci. Technol.    2024, 169: 1-10.   DOI: 10.1016/j.jmst.2023.05.064 Abstract （82）      PDF       Knowledge map    Conductive hydrogels have attracted extensive attention owing to their promising application prospects in flexible and wearable electronics. However, achieving both high sensitivity and mechanical robustness remains challenging. Herein, a novel and versatile conductive hydrogel based on the hybrid assembly of conductive cellulose nanofiber (CNF) networks has been designed and fabricated. Assisted by the templating effect of CNFs and stabilizing effect of negatively charged poly(styrene sulfonate) (PSS), conducting polymer poly (3, 4-ethylenedioxythiophene) (PEDOT) was self-organized into three-dimensional nanostructures which constructed a robust conductive network after in-situ oxidative polymerization. The unique structure derived from CNF bio-template endowed polyacrylamide (PAM) hydrogels with improved electrical conductivity and excellent mechanical performance. As a result, the as-fabricated CNF/PEDOT:PSS/PAM hydrogel exhibited an ultimate tensile strain of 1881% and toughness of 3.72 MJ/m3, which were 4.07 and 8.27 times higher than the CNF-free hydrogel, respectively. More significantly, the resultant hydrogel sensor showed highly desirable sensing properties, including remarkable sensing range (1100%), high gauge factor (GF = 5.16), fast response time (185 ms), and commendable durability, as well as good adhesiveness. Moreover, the hydrogel sensor was able to distinguish subtle physiological activities including phonation and facial expression, and monitor large human body motions such as finger flexion and elbow blending. Besides, it was feasible to integrate the strain sensor on the joints of robots to recognize complicated machine motion signals, showing potential in advanced human-machine interactions. Reference | Related Articles | Metrics Select PVDF/6H-SiC composite fiber films with enhanced piezoelectric performance by interfacial engineering for diversified applications Linlin Zhou, Tao Yang, Chunyu Guo, Kang Wang, Enhui Wang, Laipan Zhu, Hailong Wang, Sheng Cao, Kuo-Chih Chou, Xinmei Hou J. Mater. Sci. Technol.    2024, 170: 238-245.   DOI: 10.1016/j.jmst.2023.04.071 Abstract （58）      PDF       Knowledge map    Piezoelectric silicon carbide (SiC) has been quite attractive due to its superior chemical and physical properties as well as wide potential applications. However, the inherent brittleness and unsatisfactory piezoelectric response of piezoelectric semiconductors remain the major obstacles to their diversified applications. Here, flexible multifunctional PVDF/6H-SiC composite fiber films are fabricated and utilized to assemble both piezoelectric nanogenerators (PENGs) and stress/temperature/light sensors. The open circuit voltage (Voc) and the density of short circuit current (Isc) of the PENG based on the PVDF/5 wt% 6H-SiC composite fiber films reach 28.94 V and 0.24 µA cm-2, showing a significant improvement of 240% and 300% compared with that based on the pure PVDF films. The effect of 6H-SiC nanoparticles (NPs) on inducing interfacial polarization and stress concentration in composite fiber films is proved by first-principles calculation and finite element analysis. The stress/temperature/light sensors based on the composite fiber film also show high sensitivity to the corresponding stimuli. This study shows that the PVDF/6H-SiC composite fiber film is a promising candidate for assembling high-performance energy harvesters and diverse sensors. Reference | Related Articles | Metrics Select Injection molding of highly filled microcrystalline cellulose/polycaprolactone composites with the aid of reversible Diels-Alder reaction Ze Pu Wang, Wen Hong Ruan, Min Zhi Rong, Ming Qiu Zhang J. Mater. Sci. Technol.    2024, 170: 246-254.   DOI: 10.1016/j.jmst.2023.07.017 Abstract （46）      PDF       Knowledge map    To tackle the challenge of producing highly filled polymer composites using the traditional injection molding technique, which is characterized by the fairly high melt viscosity that makes mold filling difficult, the authors propose a solution based on dynamic covalent chemistry. As demonstrated by the proof-of-concept experiments, the 4-arm star-shaped polycaprolactone (PCL) oligomers and microcrystalline cellulose (MCC) are crosslinked by the reversible Diels-Alder (DA) bonds. The flowability of the compounds greatly decreases due to the dissociation of the intercomponent DA bonds at the retro-reaction temperature, and the networked architecture is reconstructed during cooling as a result of the forward DA reaction. Consequently, the high-loading MCC fillers are well distributed in the matrix and covalently bonded to the nearby PCL, forming a striking contrast to the control in which linear PCL acts as the matrix. The DA bonds crosslinked biodegradable PCL composites exhibit decent mechanical strength (20.7 MPa) even at the MCC fraction of 65 wt%, which is superior to those (5-12.2 MPa) of the highly filled PCL composites (with filler contents of 50-63.8 wt%) reported so far. The proposed approach has sufficient expansibility for the fabrication of the highly filled polymer composites constructed by other types of matrix and fillers. Reference | Related Articles | Metrics Select Regulating the intrinsic electronic structure of carbon nanofibers with high-spin state Ni for sodium storage with high-power density Zhijia Zhang, Gang Xie, Yuefang Chen, Yanhao Wei, Mengmeng Zhang, Shulei Chou, Yunxiao Wang, Yifang Zhang, Yong Jiang J. Mater. Sci. Technol.    2024, 171: 16-23.   DOI: 10.1016/j.jmst.2023.07.009 Abstract （45）      PDF       Knowledge map    Carbon nanofibers (CNFs) with high specific surface area show great potential for sodium storage as a hard carbon material. Herein, CNFs anchored with Ni nanoparticles (CNFs/Ni) were prepared through chemical vapor deposition and impregnation reduction methods, in situ growing on the three-dimensional porous copper current collector (3DP-Cu). The coupling effect of high-spin state Ni nanoparticles leads to the increase of defect density and the expansion of lattice spacing of CNFs. Meanwhile, the 3DP-Cu ensures a high loading capacity of CNFs and short ion/electron transport channels. As an integral binder-free anode, the 3DP-Cu/CNFs/Ni exhibits excellent electrochemical performance, which demonstrates a high specific capacity with 298.5 mAh g-1 at 1000 mA g-1 after 1500 cycles, and a high power density with 200 mAh g-1 over 1000 cycles at 5000 mA g-1. Density functional theory calculation results show that the high-spin state Ni regulates the electronic structure of CNFs, which significantly reduces the adsorption energy for Na+ (-2.7 Ev) and thus enables high-rate capability. The regulation of the electronic structure of carbon materials by high-spin state metal provides a new strategy for developing high-power carbonaceous anode materials for sodium-ion batteries. Reference | Related Articles | Metrics Select Effect of Al2O3 fiber on twin intersections-induced dynamic recrystallization in fine-grained TiAl matrix composite Yaofeng Luo, Yan Wang, Li Wang, Bin Liu, Yong Liu J. Mater. Sci. Technol.    2024, 172: 1-14.   DOI: 10.1016/j.jmst.2023.07.013 Abstract （45）      PDF       Knowledge map    Dynamic recrystallization (DRX) is of great significance for the thermomechanical processing and microstructural regulation of TiAl intermetallics. However, the underlying DRX mechanism remains poorly understood. In this study, an Avrami kinetics model for DRX was established, which was capable of predicting the DRX fraction accurately. In addition, the effect of Al2O3 short fiber on the DRX mechanisms of TiAl matrix composite during the isothermal compression was investigated for the first time. The results showed that other than inhibiting DRX by particles in the TiAl matrix composites, the addition of Al2O3 short fiber accelerated a novel DRX process, which was induced by twinning and twin intersections (TDRX). Thus, this composite exhibited a higher DRX rate than that of the as-cast TiAl monolithic alloy. The origin of the twin intersection and TDRX for the composite was revealed. The stress concentration near the Al2O3 fiber was above the critical shear stress for twinning and thus was favorable for the formation of twinning and twin intersections. The high stored strain energy at the regions of twins and twin intersections provided the driving force for TDRX. TDRX accelerated the grain refinement in the TiAl matrix near the Al2O3 fiber. The present findings would provide a new perspective on DRX mechanisms, and provide the scientific guidance for optimizing the microstructures of TiAl matrix composites. Reference | Related Articles | Metrics Select Flexible thermocouple using a thermoelectric graphene fiber with a seamless junction Seungwon Kim, Soomook Lim, Myeong Hee Jeong, Wonjoon Kim, Seunghyun Baik, Ji Won Suk J. Mater. Sci. Technol.    2024, 172: 15-22.   DOI: 10.1016/j.jmst.2023.05.078 Abstract （47）      PDF       Knowledge map    Temperature is an important physical variable that indicates the condition of the human body and artificial systems. Advanced wearable applications require the development of temperature sensors with different form factors. In this study, a fiber-shaped thermoelectric temperature sensor is fabricated using a continuous graphene fiber whose two halves possess different reduction states. A seamless junction is formed by partially reducing a wet-spun graphene oxide fiber with hydroiodic acid (HI) solutions of different concentrations. One-half of the fiber is mildly reduced with 0.97 wt% HI, while the other half is highly reduced with 30.6 wt% HI. The different reduction states of the graphene composite fiber result in different Seebeck coefficients, allowing for the fabrication of a fiber-shaped graphene thermocouple without any laborious assembly. The flexible graphene thermocouple exhibits high sensitivity with a thermopower of 12.5 μV K-1 in the temperature range of room temperature to ～70 °C. Furthermore, it exhibits high linearity with a correlation coefficient exceeding 0.995 and fast response with a time constant of 0.24 s. Owing to its mechanical robustness and flexibility, the stand-alone graphene thermocouple can be knitted into a cotton fabric glove, which presents a fast response to environmental changes without any external power source. This work offers a unique fabrication method for producing a high-performance, flexible thermocouple that features a seamless and clear junction without the use of additional materials. This alternative method eliminates the complicated assembly processes typically required for conventional thermocouples. Reference | Related Articles | Metrics Select Constructing globally consecutive 3D conductive network using P-doped biochar cotton fiber for superior performance of silicon-based anodes Jun Cao, Jianhong Gao, Kun Wang, Zhuoying Wu, Xinxin Zhu, Han Li, Min Ling, Chengdu Liang, Jun Chen J. Mater. Sci. Technol.    2024, 173: 181-191.   DOI: 10.1016/j.jmst.2023.07.026 Abstract （64）      PDF       Knowledge map    The inferior conductivity and drastic volume expansion of silicon still remain the bottleneck in achieving high energy density Lithium-ion Batteries (LIBs). The design of the three-dimensional structure of electrodes by compositing silicon and carbon materials has been employed to tackle the above challenges, however, the exorbitant costs and the uncertainty of the conductive structure persist, leaving ample room for improvement. Herein, silicon nanoparticles were innovatively composited with eco-friendly biochar sourced from cotton to fabricate a 3D globally consecutive conductive network. The network serves a dual purpose: enhancing overall electrode conductivity and serving as a scaffold to maintain electrode integrity. The conductivity of the network was further augmented by introducing P-doping at the optimum doping temperature of 350 °C. Unlike the local conductive sites formed by the mere mixing of silicon and conductive agents, the consecutive network can affirm the improvement of the conductivity at a macro level. Moreover, first-principle calculations further validated that the rapid diffusion of Li+ is attributed to the tailored electronic microstructure and charge rearrangement of the fiber. The prepared consecutive conductive Si@P-doped carbonized cotton fiber anode outperforms the inconsecutive Si@Graphite anode in both cycling performance (capacity retention of 1777.15 mAh g-1 vs. 682.56 mAh g-1 after 150 cycles at 0.3 C) and rate performance (1244.24 mAh g-1 vs. 370.28 mAh g-1 at 2.0 C). The findings of this study may open up new avenues for the development of globally interconnected conductive networks in Si-based anodes, thereby enabling the fabrication of high-performance LIBs. Reference | Related Articles | Metrics Select Facile synthesis of FeNi nanoparticle-loaded carbon nanocomposite fibers for enhanced microwave absorption performance Jinhu Hu, Zhengguo Jiao, Xukang Han, Jiao Liu, Mingliang Ma, Jialin Jiang, Yongbo Hou, Xingyue Wang, Chao Feng, Yong Ma J. Mater. Sci. Technol.    2024, 175: 141-152.   DOI: 10.1016/j.jmst.2023.07.053 Abstract （46）      PDF       Knowledge map    The advantages of Fe, Ni metals and one-dimensional (1D) carbon materials are combined in this study using a simple method to prepare FeNi/C nanofibers for electromagnetic microwave (EM) absorption. The prepared FeNi/C nanofibers exhibit excellent EM absorption performance under dielectric/magnetic synergistic effect. At a frequency of 13.3 GHz, the minimum reflection loss (RLmin) reaches -57.15 dB, and effective absorption bandwidth (EAB) is as high as 4.0 GHz (12.5-16.5 GHz), with a thickness and filling rate of only 1.6 mm and 30 wt.%, respectively. Analysis shows that the EM absorption performance of FeNi/C nanofibers far exceeds that of single-component nanofibers and pure carbon fibers, and the excellent EM absorption performance is due to its unique microstructure and excellent electromagnetic properties. The FeNi alloy loaded on carbon nanofibers forms rich heterogeneous interfaces, and the three-dimensional (3D) conductive network composed of 1D carbon fibers increases the migration path of electrons. In addition, FeNi alloy, as an impedance regulation factor, strengthens the dielectricity of the carbon matrix while providing multidimensional magnetism, achieving impedance matching. This work is thought to contribute to the promotion of emerging absorbers by providing a novel strategy for the development of new 1D magnetic carbon-based high-performance EM absorbing materials. Reference | Related Articles | Metrics Select Near zero thermal performance loss of Al-Si microcapsules with fibers network embedded Al2O3/AlN shell J.X. Zhang, M.J. Zhang, H.F. Li, H.Z. Gu, D. Chen, C.H. Zhang, Y.F. Tian, E.J. Wang, Q.N. Mu J. Mater. Sci. Technol.    2024, 176: 48-56.   DOI: 10.1016/j.jmst.2023.07.060 Abstract （34）      PDF       Knowledge map    Al-Si alloy, a high temperature phase change material, has great potential in thermal management due to its advantages of high heat storage density and thermal conductivity. Microencapsulation of Al-Si alloy is one of the effective techniques to solve high temperature leakage and corrosion. In this paper, commercial Al-10Si alloy micro powders were encapsulated with flexible ceramic shells whose total thickness is below 1 µm by hydrothermal treatment and heat treatment in N2 atmosphere. The compositions and microstructures were characterized by XRD, SEM and TEM. The shell was composed of AlN fibers network structure embedded with α-Al2O3/AlN which prevented the alloy from leaking and oxidizing, as well as had excellent thermal stability. The latent heat of microcapsules was 351.8 J g-1 for absorption and 372.7 J g-1 for exothermic. The microcapsules showed near zero thermal performance loss with latent heat storage (LHS)/ release (LHR) was 353.2/ 403.7 J g-1 after 3000 cycles. Compared with the published Al-Si alloy microcapsules, both high heat storage density and super thermal cycle stability were achieved, showing promising development prospects in high temperature thermal management. Reference | Related Articles | Metrics Select Augmenting reactive species over MgIn2S4-In2O3 hybrid nanofibers for efficient photocatalytic antibacterial activity Lina Wang, Peiyi Yan, Huairui Chen, Zhuo Li, Shu Jin, Xiaoxiang Xu, Jun Qian J. Mater. Sci. Technol.    2024, 176: 83-90.   DOI: 10.1016/j.jmst.2023.07.059 Abstract （36）      PDF       Knowledge map    Narrow bandgap semiconductor MgIn2S4 has been readily grown onto In2O3 nanofibers by an in situ growing method. The so-formed MgIn2S4-In2O3 hybrid nanofibers are characterized by strong visible light absorption and intimate MgIn2S4/In2O3 heterointerfaces. Under visible light illumination (λ ≥ 400 nm), the hybrid nanofibers demonstrate an exceptionally high photocatalytic activity for Escherichia coli (E. coli) disinfection, outcompeting pristine MgIn2S4, naked In2O3 nanofibers, and many other photocatalytic systems reported. Specifically, the hybrid nanofibers achieve a 7 log reduction in viable cells for merely 20 min illumination while pristine MgIn2S4 and naked In2O3 nanofibers alone are almost inactive. Further analysis indicates that the hybrid nanofibers essentially form a type-II semiconductor heterojunctions which enable spatial separation of photocarriers. Owing to the intimate heterointerfaces, photocarriers can be promptly separated and accumulated respectively in In2O3 and MgIn2S4 thereby allowing continuous generation of copious reactive species for disinfection. This work signifies the usefulness of heterointerfaces in promoting photocarrier separation and provides a useful strategy to upgrade photocatalytic performance from otherwise almost inactive semiconductors. Reference | Related Articles | Metrics Select An embedded ReS2@MAPbBr3 heterostructure with downhill interfacial charge transfer for photocatalytic upgrading of biomass-derived alcohols to aldehydes and H2 Tao Shan, Yanbo Li, Sunzai Ke, Bo Su, Lijuan Shen, Sibo Wang, Xuhui Yang, Min-Quan Yang J. Mater. Sci. Technol.    2024, 179: 155-165.   DOI: 10.1016/j.jmst.2023.08.009 Abstract （36）      PDF       Knowledge map    Solar-driven selective upgrading of lignocellulosic biomass-derived alcohols to value-added chemicals and clean fuel hydrogen (H2) shows great potential for tackling the energy crisis and environmental pollution issues. Here, we construct a MAPbBr3/ReS2 heterostructure by embedding distorted tetragonal (1T) phase ReS2 nanoflowers into large-sized MAPbBr3 for green value-added utilization of biomass-derived alcohols. The embedded structure effectively enlarges the contact interface between the ReS2 and the MAPbBr3, and importantly, induces a strong built-in electric field aligned between the spatially well-defined MAPbBr3 and ReS2 nanoflowers. Moreover, the distorted 1T phase ReS2 with low work function well matches the energy band of MAPbBr3, forming a heterostructure with a downward band bending at the interface. These features empower the MAPbBr3/ReS2 photocatalyst with high capability to promote charge separation and expedite the surface redox reaction. Consequently, optimal BAD and H2 production rates of about 1220 μmol h-1 g-1 are realized over a MAPbBr3/ReS2 2% sample, which are approximately 9 times greater than those of blank MAPbBr3. This work demonstrates the great potential of constructing an embedded transition metal dichalcogenide@metal halide perovskites heterostructure with downhill interfacial charge transfer for photocatalytic upgrading of biomass-derived alcohols. Reference | Related Articles | Metrics Select Fluorine-containing polyimide nanofiber membranes for durable and anti-aging daytime radiative cooling Qiaoran Zhang, Tiantian Xue, Yang Lu, Lei Ma, Dingyi Yu, Tianxi Liu, Wei Fan J. Mater. Sci. Technol.    2024, 179: 166-173.   DOI: 10.1016/j.jmst.2023.07.011 Abstract （39）      PDF       Knowledge map    Personal daytime radiative cooling (PDRC) materials have high sunlight reflection and high selective emissivity to outer space in the main atmospheric window, demonstrating huge potential in energy-saving for sustainable development. Recently, polymer-based membranes for radiative cooling have been widely reported, due to their easy processing, low cost, and unique optical performance. However, the desired high sunlight reflectance of PDRC materials is easily dampened by environmental aging, high temperature, and ultraviolet (UV) irradiation, resulting in reduced cooling performance for most polymers, adverse to large-scale practical applications. In this work, we demonstrate a novel polyimide nanofiber (PINF) membrane with a fluorine-containing structure via typical electrospinning technology. The resultant PINF membrane exhibits high sunlight reflectance, UV resistance, and excellent thermal stability, rendering anti-aging daytime radiative cooling. The sunlight reflectance of PINF membranes could maintain constant in the aging test for continuous 720 h under outdoor solar irradiation, exhibiting durable and long-term personal daytime radiative cooling performance. Reference | Related Articles | Metrics Select Durably and intrinsically antibacterial polyamide 6 (PA6) via backbone end-capping with high temperature-resistant imidazolium Wenwen Wang, Liting Yi, Congang Fu, Xiaoguang Li, Ting Bai, Zhong Yan, Zhentan Lu, Dong Wang J. Mater. Sci. Technol.    2024, 180: 118-128.   DOI: 10.1016/j.jmst.2023.08.028 Abstract （38）      PDF       Knowledge map    The antibacterial polyamide 6 (PA6) material has attracted great research interest due to its wide application in food packaging, biomedical fields, functional textiles, and other fields. However, it is still a challenge to prepare intrinsically antibacterial PA6 with highly efficient and durably antibacterial activity via polymerization. Herein, the antibacterial imidazolium ionic liquid of 3-carboxymethyl-1-decyl imidazole chloride was designed and synthesized for adapting the polymerization and processing temperature of PA6. Then antibacterial PA6 (PA6-IL) was synthesized through hydrolyzed ring-opening copolymerization with imidazolium at the end of the backbones. Compared to physical blending or post-modification methods, antibacterial agents as end-capping reagents of polymer backbones endowed PA6 with intrinsic antibacterial activity. As expected, the obtained PA6-IL exhibited not just comparable physicochemical and mechanical properties to conventional PA6 but excellent antibacterial activity of low antibacterial time to 60 min and durability for 28 days. Additionally, the corresponding electrospun PA6-IL nanofibrous membranes showed homogenous morphology and remarkable hydrophilicity of 7.7° as well as the high-efficient antibacterial activity. Melt-spun PA6-IL microfibers revealed a smooth surface as well as enhanced tensile strength and increased breaking elongation compared to those of conventional PA6. The PA6-IL microfibers also behaved with excellent antibacterial efficiency and durability. Accordingly, this work provides a feasible and straightforward strategy to prepare durably and intrinsically antibacterial PA6 materials especially PA6 fibers, which can be widely applied in the textiles field. Reference | Related Articles | Metrics Select A wood pulp sponge cleaning wipe as a high-performance bioanode material in microbial electrochemical systems for its vast biomass carrying capacity, large capacitance, and small charge transfer resistance Pinpin Yang, Yaqian Gao, Weihua He, Jingkun An, Jia Liu, Nan Li, Yujie Feng J. Mater. Sci. Technol.    2024, 181: 1-10.   DOI: 10.1016/j.jmst.2023.08.065 Abstract （146）      PDF       Knowledge map    Microbial electrochemical systems are a promising green and sustainable technology that can transform waste into electricity. Improving conversion efficiency and lowering system costs, particularly for electrodes, are the primary directions that promote practical application. Cellulose sponges made from wood pulp have been industrially mass-produced in various application scenarios due to their porosity and green sustainability. In this study, the three-dimensional (3D) porous cellulose sponges carbon (CSC) was obtained by directly carbonizing cellulose sponges at different temperatures (600, 700, 800, 900, 1000, and 1100 °C). It has been successfully used as a high-performance anode in microbial fuel cells (MFCs). The carbonization temperature significantly impacted the materials' specific surface area, conductivity, and capacitance. The greater the anode material's carbonization temperature, the lower the charge transfer resistance and the higher the maximum power density (CSC-1100, 4.1 ± 0.1 W m-2). The CSC-700′s maximum power density (3.62 ± 0.11 W m-2) was the highest power density reported to date among lignocellulose-based anodes with relatively low energy consumption. The pleated multilayer porous surface promotes microbial adhesion and can build thicker biofilms with the highest biomass of 2661 ± 117 μg cm-2 (CSC-1100) and containing 86 % electrogenic bacteria (Geobacter). To investigate the effect of conducting polymers on the material's surface, we introduced polyaniline and polypyrrole. We found that the CSC-1000/PPy bioanodes produced a maximum power density (4.18 ± 0.05 W m-2), slightly higher than of without polypyrrole-modified (CSC-1000, 3.99 ± 0.06 W m-2), indicating that the CSCs anode surface had excellent electron transfer efficiency and could achieve the same amount of energy as the polypyrrole surface. This study introduced a promising method for fabricating high-performance anodes using low-cost, industrialized, and sustainable materials. Reference | Related Articles | Metrics Select Aligned nanofibers incorporated composite solid electrolyte for high-sensitivity oxygen sensing at medium temperatures Mengfei Zhang, Lei Yao, Yan Xing, Jing Cheng, Tianrang Yang, Jianguo Liu, Wei Pan J. Mater. Sci. Technol.    2024, 181: 189-197.   DOI: 10.1016/j.jmst.2023.08.070 Abstract （42）      PDF       Knowledge map    Potentiometric oxygen sensors have been widely used in internal combustion engines, industrial boilers, and metallurgical heat treatment furnaces. However, traditional oxygen sensors based on yttria-stabilized zirconia (YSZ) electrolyte can only be operated at elevated temperatures (> 750 °C) due to their relatively low ionic conductivity. In this study, we present a highly efficient micro-oxygen sensor that can be operated at a temperature as low as 300 °C. This micro-oxygen sensor incorporates a composite solid electrolyte, i.e., well-aligned gadolinium-doped cerium oxide (CGO) nanofibers embedded within a YSZ matrix (YSZ/CGOf). The arrays of CGO nanofibers in the YSZ matrix are parallel to the conduction direction, providing rapid conducting channels for oxygen ions. Benefitting from this design, the composite electrolyte leads to a conductivity of four times higher than that of traditional YSZ solid electrolytes at low temperatures. This enhancement in conductivity is attributed to the presence of a defective interfacial region between CGOf and YSZ, which promotes the mobility of oxygen ions. The strategy of constructing fast ionic conduction in the composite electrolyte by using well-aligned nanofibers may be considered for the design and optimization of other micro/nano-devices including sensors, batteries, and fuel cells. Reference | Related Articles | Metrics Select Significantly improved interfacial properties of silicon dioxide nanowire functionalized poly(p-phenylene-2,6-benzobisoxazole) (PBO) fibers/polytetrafluoroethylene (PTFE) wave-transparent laminated composites Xusheng He, Chao Xiao, Huichao Du, Yanyan Wang, Xin Ding, Kang Zheng, Meng Xue, Xingyou Tian, Xian Zhang J. Mater. Sci. Technol.    2024, 183: 232-240.   DOI: 10.1016/j.jmst.2023.09.052 Abstract （42）      PDF       Knowledge map    Poly(p-phenylene-2,6-benzobisoxazole) (PBO) fiber and polytetrafluoroethylene (PTFE) resin have been widely acknowledged as excellent wave-transparent materials for future high-frequency applications due to their exceptional dielectric properties. However, the weak interfacial bonding between these two materials hampers their full potential. In this study, we successfully addressed this limitation by enhancing the surface roughness of PBO fibers and introducing active sites through the in-situ grafting of silica nanowires. The added silica acted as an interfacial anchor on the PBO fiber surface, significantly improving the bonding force between PBO and PTFE. PBO/PTFE wave-transparent laminated composites were fabricated using hot compression molding. The results demonstrate that the PBO (treated with in-situ grown silica)/PTFE laminated composites exhibit superior interlaminar shear strength (ILSS), flexural strength, flexural modulus, and tensile modulus compared to the pristine PBO/PTFE laminated composites. Specifically, these properties are found to be 58.6%, 32.9%, 138.1%, and 25.35% higher, respectively. Additionally, these composites demonstrate low dielectric constant and dielectric loss. Most notably, they achieve a wave transmittance of 91.45% at 10 GHz, indicating significant potential for wide-range applications in next-generation advanced military weapons, such as “lightweight/high-strength/wave-transparent” electromagnetic window materials, as well as civilian communication base stations. Reference | Related Articles | Metrics Select Bionic-leaf vein inspired breathable anti-impact wearable electronics with health monitoring, electromagnetic interference shielding and thermal management Xinyi Wang, Yan Tao, Chunyu Zhao, Min Sang, Jianpeng Wu, Ken Cham-Fai Leung, Ziyang Fan, Xinglong Gong, Shouhu Xuan J. Mater. Sci. Technol.    2024, 188: 216-227.   DOI: 10.1016/j.jmst.2023.11.038 Abstract （59）      PDF       Knowledge map    Breathable and stretchable conductive materials are ideal for healthcare wearable electronic devices. However, the tradeoff between the sensitivity and detection range of electronic sensors and the challenge posed by simple-functional electronics limits their development. Here, inspired by the bionic-leaf vein conductive path, silver nanowires (AgNWs)-Ti3C2Tx (MXene) hybrid structure assembled on the nonwoven fabrics (NWF) is well sandwiched between porous polyborosiloxane elastomer (PBSE) to construct the multifunctional breathable wearable electronics with both high anti-impact performance and good sensing behavior. Benefiting from the high conductive AgNWs-MXene hybrid structure, the NWF/AgNWs-MXene/PBSE nanocomposite exhibits high sensitivity (GF = 1158.1), wide monitoring range (57 %), controllable thermal management properties, and excellent electromagnetic interference shielding effect (SET = 41.46 dB). Moreover, owing to the wonderful shear stiffening effect of PBSE, the NWF/AgNWs-MXene/PBSE possesses a high energy absorption performance. Combining with deep learning, this breathable electronic device can be further applied to wireless sensing gloves and multifunctional medical belts, which will drive the development of electronic skin, human-machine interaction, and personalized healthcare monitoring applications. Reference | Related Articles | Metrics Select Robust liquid metal reinforced cellulose nanofiber/MXene composite film with Janus structure for electromagnetic interference shielding and electro-/photothermal conversion applications Hui Zhao, Tong Gao, Jin Yun, Lixin Chen J. Mater. Sci. Technol.    2024, 191: 23-32.   DOI: 10.1016/j.jmst.2023.12.035 Abstract （47）      PDF       Knowledge map    MXene-based composite films are regarded as up-and-coming multifunctional electromagnetic interfer-ence (EMI) shielding materials. However, the conflict between strong mechanical properties and high electrical conductivity hinders their application in modern integrated electronics. Herein, in virtue of density-induced sedimentation, robust and multifunctional liquid metals-reinforced cellulose nanofibers (CNF)/MXene (LMs-CNF/MXene) composite films with Janus structure are fabricated by one-step vacuum-assisted filtration method. Not only does the nacre-like structure of the CNF/MXene layer not destroy, but the deposited liquid metals (LMs) layer can serve as conductive potentiation. Due to the special Janus structure, an “absorption-reflection-reabsorption”shielding process is created in LMs-CNF/MXene composite film to strengthen EMI shielding performance. Its shielding effectiveness can reach 51.9 dB at ～27 μm, and the reflection coefficient falls to 0.89, below those of reported MXene-based shielding films. Meanwhile, the CNF/MXene layer can endow composite films with excellent mechanical properties with a super tensile strength of 110.3 MPa. Notably, the LMs-CNF/MXene EMI shielding composite films also integrate outstanding photo-/electrothermal conversion performances, which can effectively deice out-doors. The robust LMs-CNF/MXene EMI shielding composite films with satisfying photo-/electrothermal performances have extensive application prospects, such as aerospace, wearable electronics, and portable electronics. Reference | Related Articles | Metrics Select Mechanical tough and stretchable quaternized cellulose nanofibrils/MXene conductive hydrogel for flexible strain sensor with multi-scale monitoring Qing-Yue Ni, Xiao-Feng He, Jia-Lin Zhou, Yu-Qin Yang, Zi-Fan Zeng, Peng-Fei Mao, Yu-Hang Luo, Jin-Meng Xu, Baiyu Jiang, Qiang Wu, Ben Wang, Yu-Qing Qin, Li-Xiu Gong, Long-Cheng Tang, Shi-Neng Li J. Mater. Sci. Technol.    2024, 191: 181-191.   DOI: 10.1016/j.jmst.2023.12.048 Abstract （65）      PDF       Knowledge map    For advanced conductive hydrogels, adaptable mechanical properties and high conductivity are essential requirements for practical application, e.g., soft electronic devices. Here, a straightforward strategy to de-velop a mechanically robust hydrogel with high conductivity by constructing complicated 3D structures composed of covalently cross-linked polymer network and two nanofillers with distinguishing dimensions is reported. The combination of one-dimensional quaternized cellulose nanofibrils (QACNF) and two-dimensional MXene nanosheets not only provides prominent and tunable mechanical properties modu-lated by materials composition, but results in electronically conductive path with high conductivity (1281 mS m-1). Owing to the uniform interconnectivity of network structure attributed to the strong macro-molecular interaction and nano-reinforced effect, the resultant hydrogel exhibits a balanced mechanical feature, i.e., high tensile strength (449 kPa), remarkable stretchability (> 1700 %), and ultra-high tough-ness (5.46 MJ m-3), outperforming those of virgin one. Additionally, the enhanced conductive characteris-tic with the aid of QACNF enables hydrogels with impressive electromechanical behavior, containing high sensitivity (maximum gauge factor: 2.24), wide working range (0-1465 %), and fast response performance (response time: 141 ms, recover time: 140 ms). Benefiting from the excellent mechanical performance, a flexible strain sensor based on such conductive hydrogel can deliver an appealing sensing performance of monitoring multi-scale deformations, from large and monotonous mechanical deformation to tiny and complex physiological motions (e.g., joint movement and signature/vocal recognition). Together, the hy-drogel material in this work opens up opportunities in the design and fabrication of advanced gel-based materials for emerging wearable electronics. Reference | Related Articles | Metrics Select Lightweight and high-strength textured fibrous Si3N4 3D scaffold seeded with β-Si3N4 particles prepared via freeze casting Qiang Zhi, Shan Zhao, Baoqiang Hou, Nanlong Zhang, Feng Li, Bo Wang, Jianfeng Yang J. Mater. Sci. Technol.    2024, 194: 75-86.   DOI: 10.1016/j.jmst.2023.12.075 Abstract （50）      PDF       Knowledge map    Highly porous Si3N4 ceramics with unidirectionally aligned pore channels are gaining significant attention across various fields due to their outstanding functional capabilities. However, achieving high strength in such unidirectional highly porous Si3N4 ceramics remains challenging. Herein, we design and fabricate a novel β-Si3N4 scaffold composed of directionally aligned lamellar walls with a textured microstructure by directionally freeze casting of α-Si3N4 suspensions with fine elongated β-Si3N4 seeds addition, followed by liquid phase sintering. During the sintering, the scaffold exhibited anisotropic shrinkage, and fibrous β-Si3N4 grains were synthesized through epitaxial growth on the seeds preferentially oriented or the nuclei originated from α-Si3N4 powders, resulting in the grains aligned parallel to lamellar walls and bridged the walls. Seed additions of 7 to 15 wt% were beneficial for the optimized distribution of the two types of β-Si3N4 grains, which contributed to the excellent resistance to bucking-induced fracture for the walls. Compared with other unidirectional porous Si3N4 prepared by freeze-casting in the literature, the Si3N4 scaffold exhibited outstanding compressive strength, ranging from 2.8 to 22.0 MPa, as the porosity decreased from 94.4 % to 88.0 % and the density increased from 175 to 365 mg/cm3. The lightweight and strong Si3N4 scaffolds are promising candidates for engineering applications in harsh environments. Reference | Related Articles | Metrics Select In-situ construction of carbon fiber gradient periodic structure in Al2O3f/SiOC composites for ultra-broadband and high-temperature electromagnetic wave absorption Fan Yang, Jimei Xue, Cunxian Wang, Jiuzheng Zhao, Shangwu Fan, Xiaomeng Fan, Laifei Cheng J. Mater. Sci. Technol.    2024, 194: 87-97.   DOI: 10.1016/j.jmst.2024.01.037 Abstract （41）      PDF       Knowledge map    Ceramic matrix composites (CMC) are widely utilized in high-temperature components of aero-engines for load-bearing and electromagnetic stealth synergy due to their superior toughening and designable electromagnetic properties. However, the design of ultra-broadband electromagnetic wave (EMW) absorption at thin thicknesses (d < 10 mm) has been difficult and focused, especially the design of metamaterial. Inspired by 3D printing technology and the structural characteristic of 2D CMC, this study ingeniously devised and proposed a novel carbon fiber gradient periodic structure in Al2O3f/SiOC composites to enhance the ultra-broadband EMW absorption properties at a wide temperature range. By optimizing the geometric structure parameters, the Al2O3f/SiOC composites with the carbon fiber gradient periodic structure have exhibited exceptional ultra-broadband EMW absorption properties at elevated temperatures and excellent mechanical performance. The composites have attained a minimum reflection loss (RLmin) of -30 dB and a high absorption efficiency of more than 84 %, ranging from 9.3 to 40 GHz at a thickness of 9 mm. Due to the temperature insensitivity of discrete periodic structures, the composites can adapt to high temperatures up to 700 °C. Additionally, compared to the Al2O3f/SiOC composites, the flexural strength and fracture toughness of the Al2O3f/SiOC composites with carbon fiber gradient periodic structure have significantly increased to 398 MPa and 15.6 MPa m1/2, respectively. This work breaks through the limitation of the design and fabrication of 3D periodic structures in CMC, creating a novel oxide-CMC with ultra-broadband EMW absorption properties at a wide temperature range and enhanced mechanical properties. Reference | Related Articles | Metrics Select Mechanical recycling of PET containing mixtures of phosphorus flame retardants Jiuke Chen, Sithiprumnea Dul, Sandro Lehner, Milijana Jovic, Sabyasachi Gaan, Manfred Heuberger, Rudolf Hufenus, Ali Gooneie J. Mater. Sci. Technol.    2024, 194: 167-179.   DOI: 10.1016/j.jmst.2024.01.035 Abstract （66）      PDF       Knowledge map    Flame-retarded polymers, such as polyester textiles and sheets, are attracting attention with regard to their sustainability. Mechanical recycling is currently the most frequently used technique for improving the circularity of plastics. However, one complication of mechanical recycling is associated with the (still) inevitable mixtures of polymers and additives, which can influence material stability and significantly deteriorate the mechanical properties of recycled products. In this study, we aim to specifically investigate the interactions between mixtures of phosphorus flame retardants (FRs) in polyethylene terephthalate (PET) and evaluate their potential role in the mechanical recycling of melt-spun fibers. Two highly relevant commercial FRs, namely a DOPO-derivative (DOPO-PEPA or DP) and Aflammit PCO 900 (AF), are added to PET compounds as additives using a melt compounder. The melt stability of PET/FR compounds over extended processing time is assessed by chemical, thermal, and rheological measurements. DP shows a molecular lubrication effect, lowering the melt viscosity of PET, while AF promotes chemical changes (i.e., chain branching/crosslinking). Interestingly, a PET compound containing hybrid mixtures of DP/AF 20/80 (wt.%/wt.%) shows the most stable behavior at high temperatures under both nitrogen and air atmospheres, thus showing a synergistic effect. Most importantly, in a recycling scenario, the stabilization effect persists at diluted concentrations below the typical FR contents in PET. Multiple extrusion cycles are used to assess the repeated processing behavior of the compounds, and the mechanical properties and fire behavior of melt-spun fibers are compared before and after recycling. The results reveal that DP can maintain the mechanical performance of recycled PET/FR fibers, even if it is mixed (contaminated) with AF. Reference | Related Articles | Metrics Select Enhanced sensing performance of superelastic thermally drawn liquid metal fibers through helical architecture while eliminating directional signal errors Yeke Zhang, Yu He, Liheng Niu, Xiaowei Xing, Yuzhi Jiang, Jian Fang, Yuqing Liu J. Mater. Sci. Technol.    2024, 195: 136-145.   DOI: 10.1016/j.jmst.2024.02.028 Abstract （30）      PDF       Knowledge map    Due to their potential use in creating advanced electronic textiles for wearable technology, functional fibers have garnered enormous interests. The presence of stretchable smart fibers has significantly expanded the application scenarios of intelligent fibers. However, preparing fibers that possess both excellent electrical performance and high stretchability remains a formidable challenge. The fabrication of stretchable multifunctional fiber-based sensors employing a scalable method is reported here. Using a thermal drawing process, the collaborative interplay between the hollow confined channels of superelastic poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) thermally drawn fibers and the high fluidity of liquid metal (LM) ensures the exceptional electrical performance of the fibers. Simultaneously, the presence of a helical structure further enhances both the sensing and mechanical properties. The helical two LM channel fiber-based sensors are capable of displaying more than 1000 % strain, high stability over 1000 cycles, a quick pressure response and release time of 30.45 and 45.35 ms, and outstanding electrical conductivity of 8.075 × 105 S/m. In addition, the electrical conductivity of this fiber increases with strain level, reaching 3 × 106 S/m when the strain is 500 %. Furthermore, due to their superior tension and compression sensing capabilities, flexible helical sensors offer considerable potential for use in wearable electronics applications such as human motion detection, Morse code compilation, multichannel sensing, and more. Reference | Related Articles | Metrics Select In situ X-ray imaging and numerical modeling of damage accumulation in C/SiC composites at temperatures up to 1200 °C Weijian Qian, Wanen Zhang, Shengchuan Wu, Yue Hu, Xiangyu Zhang, Qiaodan Hu, Shaoming Dong, Shantung Tu J. Mater. Sci. Technol.    2024, 197: 65-77.   DOI: 10.1016/j.jmst.2024.01.069 Abstract （38）      PDF       Knowledge map    Carbon fiber reinforced silicon carbide matrix composites (C/SiC) have emerged as key materials for thermal protection systems owing to their high strength-to-weight ratio, high-temperature durability, resistance to oxidation, and outstanding reliability. However, manufacturing defects deteriorate the mechanical response of these composites under extreme thermal-force coupling conditions, prompting significant research attention. This study demonstrates a customized in situ loading device compatible with synchrotron radiation facilities, enabling high spatial and temporal resolution recording of internal material damage evolution and failure behavior under thermal-force coupling conditions. Infrared thermal radiation units in a confocal configuration were used to create ultra-high-temperature environments, offering advantages of compactness, rapid heating, and versatility. In situ tensile tests were conducted on C/SiC samples in a nitrogen atmosphere at both room temperature and 1200 °C. The high-resolution image data demonstrate various failure phenomena, such as matrix cracking and pore linkage. Image-based finite element simulations indicate that the temperature-dependent variation of the failure mechanism is attributable to thermal residual stresses and defect-induced stress concentrations. This work seamlessly integrates extreme mechanical testing methods with in situ observation techniques, providing a comprehensive solution for accurately quantifying crack initiation, pore connection, and failure behavior of C/SiC composites. Reference | Related Articles | Metrics Select Enhanced interfacial bonding of AF/PEEK composite based on CNT/aramid nanofiber multiscale flexible-rigid structure Nan Zhou, Long Xia, Naiyu Jiang, Yingze Li, Hanxiong Lyu, Hongyan Zhang, Xiaohu Zou, Wenbo Liu, Dongxing Zhang J. Mater. Sci. Technol.    2024, 197: 139-148.   DOI: 10.1016/j.jmst.2024.02.015 Abstract （38）      PDF       Knowledge map    The application of aramid fiber (AF)/polyetheretherketone (PEEK) composites is currently hindered by the inert surface and poor wettability of AF, resulting in weak interfacial adhesion and poor mechanical properties. Surface coating and the introduction of nanostructures have been proven to be effective approaches to address this problem. Herein, a simple hybrid sizing agent has been developed to modify the AF surface, consisting of soluble polyimide (PI) as a compatibilizer, carboxyl-functionalized carbon nanotubes (CNT-COOH) as a rigid unit, and aramid nanofibers (ANF) as a flexible component. The synergetic effects of PI and the multiscale flexible-rigid structure (CNT-COOH/ANF) contribute to the formation of chemical and physical bonds between AF and PEEK matrix, further improving the interfacial adhesion and stress transfer efficiency. Attributed to the enhanced wettability and roughness of AF, compared with unsized AF, the flexural strength (220.97 MPa), modulus (13.26 GPa), ILSS (13.36 MPa), and storage modulus (12.93 GPa) of the AF/PEEK composite increase by 132.60 %, 99.00 %, 18.97 %, and 82.70 % respectively. Additionally, the flexible-rigid nanonetwork facilitates the penetration of the PEEK resin into pore spaces. This simple and effective approach exhibits promising potential in enhancing the interfacial bonding of AF/PEEK composites. Reference | Related Articles | Metrics Select Layered composites made of polymer derived SiOC/ZrB2 reinforced by ZrO2/SiO2 fibers with simultaneous microwave absorption and thermal insulation Yumeng Deng, Bin Ren, Yujun Jia, Qian Wang, Hejun Li J. Mater. Sci. Technol.    2024, 196: 50-59.   DOI: 10.1016/j.jmst.2023.12.053 Abstract （42）      PDF       Knowledge map    To simultaneously improve the microwave absorption and thermal insulation properties of the ceramic materials for stealth high-speed vehicles, layered composites made of polymer-derived SiOC/ZrB2 reinforced by ZrO2/SiO2 fibers were reported in this work. The composites possess a continuous multilayer structure, which was fabricated via the precursor impregnation assisted by hot press curing and pyrolysis using the transparent ZrO2/SiO2 fibers and polymer-derived SiOC and nano ZrB2. The layered composites show an effective absorption band (EAB) of 4.2 GHz at a thickness of 2.9 mm and a minimum reflection loss of -59.34 dB. The exceptional electromagnetic (EM) wave attenuation capability is ascribed to the impedance matching as well as massive EM wave loss caused by the multilayers in which the nano ZrB2 provides interfacial polarization and electrical conduction loss. With a design of the multi-curvature arch structure, a remarkable reduction of radar cross section can be achieved. Besides, the layered composites exhibit good oxidation resistance and thermal insulation when exposed to the dynamic heating environment, demonstrating the potential application in harsh environments used for multifunctional electromagnetic absorbing materials. Reference | Related Articles | Metrics Select Comparative study of flame retardancy in polyimine vitrimers and composites: Evaluating additive and reactive flame retardants acting via gas-, solid-, and combined-phase mechanisms Andrea Toldy, Dániel István Poór, Beáta Szolnoki, Boglárka Devecser, Norbert Geier, Ákos Pomázi J. Mater. Sci. Technol.    2024, 196: 101-111.   DOI: 10.1016/j.jmst.2024.01.047 Abstract （34）      PDF       Knowledge map    We developed flame retarded polyimine type vitrimers and carbon fibre reinforced composites using two additive and a reactive flame retardant containing phosphorus: ammonium polyphosphate (APP), resorcinol bis(diphenyl phosphate) (RDP); and N,N',N''-tris(2-aminoethyl)-phosphoric acid triamide (TEDAP). We characterised the vitrimer matrix materials by differential scanning calorimetry (DSC), thermal analysis (TGA), limiting oxygen index (LOI), UL-94 test and mass loss calorimetry (MLC), while the vitrimer composites by LOI, UL-94 test, MLC and dynamic mechanical analysis (DMA). We compared the performance of the vitrimer systems to a benchmark pentaerythritol-based aliphatic epoxy resin system (PER). The vitrimer reference had higher thermal stability but lower fire performance than the PER aliphatic reference epoxy. At lower phosphorus content, the vitrimer systems exhibited a melting above their vitrimer transition temperature, which negatively affected their LOI and UL-94 results. From 2% phosphorus content, rapid charring and extinguishing of vitrimers prevented the softening and deforming. The superior performance of these same flame retardants in vitrimer systems could be attributed to the high nitrogen content of imine-based vitrimers in combination with phosphorus flame retardants, exploiting nitrogen-phosphorus synergism. In both matrices, flame retardants with solid phase action lead to better fire performance, while in composites, the lowest peak heat release rates (152 kW/m2 in vitrimer composite) were achieved with RDP acting predominantly in the gas phase, as carbon fibres hindered the intumescent phenomenon. Reference | Related Articles | Metrics Select Vertical graphene-decorated carbon nanofibers establishing robust conductive networks for fiber-based stretchable strain sensors Hyeon-Jong Lee, Seung Chan Na, TaeGyeong Lim, Jeongmin Yun, Yonas Tsegaye Megra, Ji-Hyun Oh, Wonyoung Jeong, Daeyoung Lim, Ji Won Suk J. Mater. Sci. Technol.    2024, 200: 52-60.   DOI: 10.1016/j.jmst.2024.01.090 Abstract （41）      PDF       Knowledge map    Stretchable strain sensors have great potential for diverse applications including human motion detection, soft robotics, and health monitoring. However, their practical implementation requires improved repeatability and stability along with high sensing performances. Here, we utilized spiky vertical graphene (VG) sheets decorated on carbon nanofibers (VG@CNFs) to establish reliable conductive networks for resistive strain sensing. Three-dimensional (3D) VG@CNFs combined with reduced graphene oxide (rGO) sheets were simply coated on stretchable spandex fibers by ultrasonication. Because of the spiky geometry of the VG sheets, VG@CNF and rGO exhibited enhanced interactions, which was confirmed by mode I fracture tests. Due to the robust conductive networks formed by the VG@CNF and rGO hybrid, the fiber strain sensor exhibited a significantly improved strain range of up to 522% (with a high gauge factor of 1358) and stable resistance changes with minimal variation even after 5000 stretching-releasing cycles under a strain of 50%. In addition, the textile strain sensor based on the VG@CNF/rGO hybrid showed even improved repeatability for various strain levels of 10% to 200%, enabling its implementation on leggings for monitoring of squat posture. This study demonstrates the high potential of the 3D VG@CNF for high-performance and reliable stretchable strain sensors. Reference | Related Articles | Metrics Select Urea-treatment of CoOx carbon nanofibers to improve the electrochemical performance of supercapacitor using aqueous electrolytes Bhavana Joshi, Seongdong Kim, Edmund Samuel, Jungwoo Huh, Mohammed S. Almoiqli, Khalid N. Alharbi, Sam S. Yoon J. Mater. Sci. Technol.    2024, 200: 83-92.   DOI: 10.1016/j.jmst.2024.02.063 Abstract （36）      PDF       Knowledge map    Supercapacitors (SCs) play a crucial role in flexible electronics, necessitating innovative approaches to enhance surface faradaic reactions and minimize faradaic diffusion while using aqueous electrolytes. Thus, the urea treatment of cobalt oxide (CoOx)-decorated carbon nanofibers (CNFs) is proposed in this study to decrease the contribution of faradaic diffusion-limited current. Flexible CoOx/CNF electrodes were obtained by annealing ZIF-67-grafted polyacrylonitrile (PAN) fibers via a wet chemical method. The urea treatment of CoOx/CNFs increased the content of sp2-hybridized carbon and pyridinic nitrogen, as confirmed by X-ray photoelectron spectroscopy, effectively enhancing conductivity and pseudocapacitive charge storage capability via nitrogen doping. Notably, urea-treated CoOx/CNF electrode samples exhibited a capacitance of 750 mF cm-2 at a scan rate of 10 mV s-1, while retaining more than 81 % capacitance at a higher scan rate of 100 mV s-1. The cyclic voltammetry curves during variable bending angle testing (0°, 45°, and 90°) exhibited negligible changes, indicating the excellent flexibility of the SCs. The CoOx/CNFs and urea-treated CoOx/CNFs exhibited 80 % and 91 % capacitance retentions, respectively, after 10,000 galvanostatic charge and discharge cycles. Furthermore, the attained energy densities of 76 and 61 µWh cm-2 at the respective power densities of 2 and 20 mW cm-2 indicated the excellent electrochemical performance of the optimal urea-treated CoOx/CNF electrode. Reference | Related Articles | Metrics

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